OCPBUGS-36526: Remove subnet requirement from IBU seed guidelines

Author: amolnar-rh

modules/cnf-image-based-upgrade-seed-image-guide.adoc

@@ -21,7 +21,6 @@ Dual-stack networking is not supported in this release.
 * Set of Day 2 Operators, including the {lcao} and the {oadp-short} Operator
 * Disconnected registry
 * FIPS configuration
-* If the target cluster has multiple IPs and one of them belongs to the subnet that was used for creating the seed image, the upgrade fails if the target cluster's node IP does not belong to that subnet.
 
 The following configurations only have to partially match on the participating clusters: